config: read (but not write) from $XDG_CONFIG_HOME/git/config file

Teach git to read the "gitconfig" information from a new location,
$XDG_CONFIG_HOME/git/config; this allows the user to avoid
cluttering $HOME with many per-application configuration files.

In the order of reading, this file comes between the global
configuration file (typically $HOME/.gitconfig) and the system wide
configuration file (typically /etc/gitconfig).

We do not write to this new location (yet).

If $XDG_CONFIG_HOME is either not set or empty, $HOME/.config/git/config
will be used. This is in line with XDG specification.

If the new file does not exist, the behavior is unchanged.

Signed-off-by: Huynh Khoi Nguyen Nguyen <Huynh-Khoi-Nguyen.Nguyen@ensimag.imag.fr>
Signed-off-by: Valentin Duperray <Valentin.Duperray@ensimag.imag.fr>
Signed-off-by: Franck Jonas <Franck.Jonas@ensimag.imag.fr>
Signed-off-by: Lucien Kong <Lucien.Kong@ensimag.imag.fr>
Signed-off-by: Thomas Nguy <Thomas.Nguy@ensimag.imag.fr>
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/path.c b/path.c
index 6f2aa699ad..66acd24fa8 100644
--- a/path.c
+++ b/path.c
@@ -87,6 +87,21 @@ char *git_pathdup(const char *fmt, ...)
 	return xstrdup(path);
 }
 
+char *mkpathdup(const char *fmt, ...)
+{
+	char *path;
+	struct strbuf sb = STRBUF_INIT;
+	va_list args;
+
+	va_start(args, fmt);
+	strbuf_vaddf(&sb, fmt, args);
+	va_end(args);
+	path = xstrdup(cleanup_path(sb.buf));
+
+	strbuf_release(&sb);
+	return path;
+}
+
 char *mkpath(const char *fmt, ...)
 {
 	va_list args;
@@ -122,6 +137,32 @@ char *git_path(const char *fmt, ...)
 	return cleanup_path(pathname);
 }
 
+void home_config_paths(char **global, char **xdg, char *file)
+{
+	char *xdg_home = getenv("XDG_CONFIG_HOME");
+	char *home = getenv("HOME");
+	char *to_free = NULL;
+
+	if (!home) {
+		if (global)
+			*global = NULL;
+	} else {
+		if (!xdg_home) {
+			to_free = mkpathdup("%s/.config", home);
+			xdg_home = to_free;
+		}
+		if (global)
+			*global = mkpathdup("%s/.gitconfig", home);
+	}
+
+	if (!xdg_home)
+		*xdg = NULL;
+	else
+		*xdg = mkpathdup("%s/git/%s", xdg_home, file);
+
+	free(to_free);
+}
+
 char *git_path_submodule(const char *path, const char *fmt, ...)
 {
 	char *pathname = get_pathname();